Polyurethane foams

ABSTRACT

The invention relates to polyurethane foams comprising  
     (i) ethylenimine, polyethylenimine, polyvinylamine, polyvinylamine copolymers, carboxymethylated polyethylenimines, phosphonomethylated polyethylenimines, quaternized polyethylenimines and/or dithiocarbamatized polyethylenimines or  
     (ii) alkali metal hydroxides and/or alkaline earth metal hydroxides or  
     a mixture of (i) and (ii).

[0001] The present invention relates to polyurethane foams, for exampleflexible, semirigid or rigid foams, preferably open-celled foams,comprising (i) ethylenimine, polyethylenimine, polyvinylamine,polyvinylamine copolymers, carboxymethylated polyethylenimines,phosphonomethylated polyethylenimines, quaternized polyethyleniminesand/or dithiocarbamatized polyethyleneimines or (ii) alkali metalhydroxides or alkaline earth metal hydroxides, to their use and to aprocess for producing them.

[0002] The production of polyurethane foams, hereinafter also referredto as PUR foams, by reacting polyisocyanates with compounds having atleast two reactive hydrogen atoms has been known for a long time and hasbeen described many times.

[0003] Owing to the advantageous properties of PUR foams, for example inrespect of their low abrasion and their resistance to chemicals, thesefoams are in principle very useful as support materials for activecompounds. The immobilization of active compounds on polymers offers theadvantages of heterogeneous reactions in both physical and chemicalprocesses. These advantages include, for example, the ready removal andrecovery of compounds, e.g. by simple filtration or regeneration,recycling and the opportunity of using the active compounds incontinuous flow processes and also the high activity due to the largesurface area of the support material.

[0004] Thus, WO 95/18159 describes the preparation of an ion-exchangematerial based on a polyurethane foam, in which the ion-exchangematerial is either added to the starting materials for the production ofthe foam or is subsequently polymerized on the foam. As ion-exchangematerial, mention is made of many polymers includingpolystyrene-polyethylenimine. The use of a polystyrene-polyethylenimineis disadvantageous for two reasons. Firstly, the polyethylenimine has tobe bound to the polystyrene in an additional process step. Secondly, theeffective amount of active compound introduced is reduced by theinactive polystyrene, compared to direct use of pglyethylenimine.

[0005] Odorous substances are usually mixtures of organic substanceswhich even in extraordinarily low concentrations lead to appreciableodor pollution. Many sorbents are available for separating off theseodorous substances; for example, it is possible to use activated carbon,silica gels, aluminas or molecular sieves. In general, these sorbentsare supported on polymeric framework substances, for example foams.

[0006] JP 03009950 describes a deodorized polyurethane foam which bindsa large number of odorous substances. Components which are deodorizedare, for example, compounds based on phosphoric acid, phosphorous acid,hypophosphorous acid, hydrochloric acid and their salts (alkaline earthmetal and alkaline metal salts). In addition, the active compounds arepreferably applied to a support (silica or alumina).

[0007] U.S. Pat. No. 4,877,816 describes a foam cloth comprising fineparticles of a deodorant and a disinfectant. Deodorants mentioned arezinc carbonate and iron sulfate, while phthalimide is mentioned asdisinfectant. Preference is given to using a polyurethane foam.

[0008] JP 49131986 discloses polyurethane foams which are impregnatedwith a solution or suspension of metallic compounds. These compounds aresubsequently treated with alkaline, oxidizing or reducing compounds toproduce metals, metal oxides or metal complexes on the foam. The foamscan be used for odor adsorption.

[0009] JP 09057050 describes a deodorizing filter comprising apolyurethane foam which comprises an active compound, e.g. activatedcarbon, an ion-exchange resin, or a catalyst.

[0010] It is an object of the present invention, to develop polymershaving excellent adsorption capabilities for various compounds, inparticular heavy metal ions and dyes. In addition, the foams producedshould also be suitable for the adsorption of anionic heavy metalcomplexes, anions of organic molecules (e.g. aldehydes or acids) and forthe purification of wastewater from paper manufacture. A further objectof the present invention is to develop a foam which reliably and quicklyreduces the concentration of odorous substances, preferably without thegas comprising odorous substances flowing through it.

[0011] We have found that this object is achieved by polyurethane foamscomprising compounds (i) and/or (ii).

[0012] The present invention accordingly provides polyurethane foamscomprising

[0013] (i) ethylenimine, polyethylenimine, polyvinylamine,polyvinylamine copolymers, carboxymethylated polyethylenimines,phosphonomethylated polyethylenimines, quaternized polyethyleniminesand/or dithiocarbamatized polyethylenimines or

[0014] (ii) alkali metal hydroxides and/or alkaline earth metalhydroxides or

[0015] a mixture of (i) and (ii).

[0016] The invention also provides a process for producing thepolyurethane foams of the present invention and provides for their usefor the adsorption of odorous substances and for producing shapedbodies.

[0017] According to the present invention, ethylenimine,polyethyleninime, polyvinylimine, polyvinylamine copolymers,carboxymethylated polyethylenimines, phosphonomethylatedpolyethylenimines, quaternized polyethyleneimines and/ordithiocarbamatized polyethylenimines are used as compounds (i).

[0018] Possible compounds (i) are, for example: ethylenimine,polyethylenimines having a mean molecular weight of from 500 to 800,000g/mol, carboxymethylated polyethylenimines having a mean molecularweight of from 1000 to 100,000 g/mol, phosphonomethylatedpolyethylenimines having a mean molecular weight of from 1000 to 100,000g/mol, quaternized polyethylenimines having a mean molecular weight offrom 1000 to 250,000 g/mol, dithiocarbamatized polyethylenimines havinga mean molecular weight of from 1000 to 250,000 g/mol, polyvinylamineshaving a mean molecular weight of from 1000 to 150,000 g/mol,polyvinylamine copolymers having a mean molecular weight of from. 1000to 250,000 g/mol. In all these cases, the figures quoted are based onthe number average molecular weight.

[0019] Preference is given to polyethylenimine and/or polyvinylamine as(i).

[0020] As alkali metal hydroxides or alkaline earth metal hydroxides(ii) to be used according to the present invention, preference is givento sodium hydroxide and potassium hydroxide.

[0021] Apart from the adsorption of heavy metal ions and odoroussubstances, the foams produced are also suitable for the adsorption ofdyes, anionic heavy metal complexes or anions. In addition, the foamscan be used for the adsorption of organic molecules (e.g. aldehydes),for the purification of wastewater from paper manufacture or for fixingacidic gases.

[0022] The polyurethane foams of the present invention are produced byreacting polyisocyanates with compounds having at least two hydrogenatoms which are reactive toward isocyanates, with the compounds (i) or(ii) being applied to the surface of the foam. The compounds (i) and(ii) can be applied to the polyurethane foam by two preferred methods.

[0023] In the first method, the polyurethane foam is produced byreacting polyisocyanates with compounds having at least two hydrogenatoms which are reactive toward isocyanates in the presence of (i) or(ii). However, prepolymers can also be prepared from the compounds (i)by reaction with isocyanate. For the present purposes, prepolymers arereaction products of compounds (i) and polyisocyanates, which preferablyhave free isocyanate groups at the end of the chain. The prepolymers andpseudoprepolymers and their preparation are generally known.

[0024] In the second method, the polyurethane foam is dipped intosolutions of the compounds (i) or (ii). Dipping the foam into the liquidcompound (i) or a solution of the solid or liquid compound (i) or (ii)in a suitable solvent results in the foam being impregnated with (i) or(ii). Suitable solvents are protic solvents, for example water, acetone,ethanol, i-propanol, methyl ethyl ketone or haloalkanes such as1,2-dichloromethane. The solvent can subsequently be removed from thefoams which have been impregnated with compound (i) or (ii). This can beachieved by applying a vacuum or by drying at up to 50° C. Thermaltreatment at from 50 to 150° C. for a period of from 4 to 72 hours canenable the compounds (i) to react with the foam and thus be covalentlybound thereto.

[0025] Furthermore, application of the compounds (i) or (ii) can becarried out, for example, by spraying on. In this case, the solvent alsohas to be removed. This can be carried out, for example, by applicationof a vacuum and/or heating.

[0026] In a subsequent impregnation of the foams with a solution of thecompounds (i) or (ii), the uptake capacity of the foam is dependent,inter alia, on the type and polarity of the solvent in which the activecompound has been dissolved. The use of acetone in particular aspreferred solvent for the compounds (i) increases the capacity of thefoam for (i). In the case of the compounds (ii), preference is given tousing alcohol, e.g. ethanol.

[0027] The compounds (i) or (ii) applied to the foam by impregnationcan, if desired, be crosslinked on the foam in a further step. Suitablecrosslinkers are generally known; examples are nonvolatile PEGbisglycidyl ethers or polycarboxylic acids such as tetracarboxylicacids. The temperatures required for crosslinking are 80° C. for theethers and from 120 to 130° C. for the polycarboxylic acids.

[0028] To achieve improved immobilization of the compound (i), the foamcan be produced using an excess of isocyanate: in this case, thecompound (i) can be fixed to the foam framework via remaining isocyanategroups.

[0029] The polyurethane foams of the present invention preferably have acontent of (i) or (ii) or mixtures of (i) and (ii) of from 0.1 to 80% byweight, preferably from 20 to 70% by weight, particularly preferablyfrom 25 to 60% by weight, based on the weight of the foam.

[0030] The polyurethane foams of the present invention are preferablyemployed in the adsorption of odorous substances and of heavy metal ionsand dyes from liquids. However, the foams can also be used for theadsorption of anionic heavy metal complexes, anions, acidic compoundsand organic substances such as formaldehyde. The foams can likewise beused for the purification of wastewater from paper manufacture. Thefoams can likewise be used for gas scrubbing, for example as ozonefilter in passenger cars.

[0031] The pollutants, in particular heavy metal ions and dyes, whichcan advantageously be adsorbed by the polyurethane foams of the presentinvention are determined by the choice of the supported complexingagent. Some heavy metals (particularly mercury and lead) are alsoadsorbed by the polyurethane foam, which effects an additional increasein the degree of removal. Heavy metals which are adsorbed by thesupported active compounds are, in particular, copper, nickel, cobalt,cadmium, mercury, lead, chromium, manganese, iron, rhenium, silver andzinc.

[0032] Liquids from which the pollutants can be adsorbed are inprinciple all liquids in which the latter are soluble and which do notdestroy the polyurethane foam matrix. Particularly useful liquids arewater, polar, water-miscible or organic solvents and any mixtures ofthese compounds. In the case of aqueous solutions, the proportion oforganic solvents is preferably not more than 30% by weight, based on theweight of the solution, since otherwise partial demixing can occurduring adsorption and lead to problems in the adsorption process.

[0033] The pollutant-containing liquid is preferably brought intocontact with the novel polyurethane foam comprising (i). Thepolyurethane foam can be introduced as geometric shaped bodies, e.g. ascubes or spheres, or in comminuted form into the liquid, stirred in thisand removed again after adsorption has occurred, for example by means offiltration. In a further embodiment of the invention, the polyurethanefoam can, for example, be fixed in a tube or a cartridge and the liquidcan be passed through this fixed foam. The foam can be fixed, forexample, as a fixed bed in an exchange column. It has been found to beuseful to employ the comminuted foam as a filter bed and to pass thesolution to be purified through this filter.

[0034] Comminuted foams are particularly suitable for the process of thepresent invention, since the available surface area is particularly highhere.

[0035] The adsorption preferably takes place at a pH in the range from 2to 12, preferably from 4 to 10. The pH can be set by means of buffersolutions. If metal hydroxides precipitate, these can likewise bephysisorbed on the foam and be separated off in this way. As buffers, itis possible to choose known buffer solutions for this pH range, e.g. acitrate buffer or a phosphate buffer.

[0036] After the exchange capacity of the polyurethane foams usedaccording to the present invention has been exhausted, it may bepossible to carry out an extraction by means of acids or complexingagents. The functionalized foam can be reused after this regeneration.

[0037] If regeneration of the foam is not possible or possible only withdifficulty, it can be thermally utilized in a financially advantageousmanner. The relevant metals may be present as alloy constituents inblast furnace metals.

[0038] The adsorption of radioactive compounds, atoms or ions enablesradiation-emitting constituents to be collected. The increase in thevolume concentration achieved in this way constitutes a great economicadvantage. The resulting contaminated PUR foams can then, ifappropriate, be encased in concrete or permanently sealed. Final storageis then possible.

[0039] The polyurethane foams of the present invention can also be usedin the form of foam pads, particularly for the adsorption of odoroussubstances. Furthermore, they can be used for producing shaped articlesand consumer goods. Examples include shoe soles, coathangers and paddingfor clothing. The production of these shaped articles also encompassesthe backfoaming of articles, for example coathangers, cupboard orwardrobe doors or dashboards in vehicles.

[0040] The adsorbent foams used according to the present invention arepreferably usable in a temperature range from >0° C. to 110° C.,although only a limited operation life is to be expected at temperaturesof >90° C.

[0041] The polyurethane foams of the present invention are preferablyopen-celled so as to provide a very large surface area for contactbetween the compounds (i) and/or (ii) and the substances to be adsorbed.

[0042] Furthermore, it is advantageous to make the polyurethane foamshydrophilic, especially those containing the compounds (i), which makesoptimum wetting of the foam with a liquid containing pollutants to beadsorbed possible. The hydrophilicity of the polyurethane foams can beincreased, for example, by the use of polyetherols having a high contentof ethylene oxide in the chain.

[0043] The polyurethane foams produced by the process of the presentinvention preferably have a density of from 10 to 800 kg/m³,particularly preferably from 20 to 700 kg/m³ and in particular from 40to 60 kg/m³.

[0044] To produce the polyurethanes of the present invention, theisocyanates are reacted in a customary manner with the compounds havingat least two active hydrogen atoms in the presence of blowing agentsand, if desired, catalysts and/or auxiliaries and/or additives. In sucha production process, the compounds having at least two hydrogen atomswhich are reactive toward isocyanate groups and the blowing agents,catalysts and auxiliaries and/or additives described below arefrequently combined to form a polyol component prior to the reaction andthis is then reacted with the isocyanate component.

[0045] As regards the possible starting materials for carrying out theprocess of the present invention, i.e. the isocyanates, the compoundshaving at least two active hydrogen atoms, the blowing agents and, ifdesired, the catalysts and/or the auxiliaries and/or additives, thefollowing details may be provided:

[0046] as isocyanates, preferably polyisocyanates, particularlypreferably diisocyanates, more preferably organic diisocyanates, it ispossible to use the customary and known (cyclo)aliphatic and aromaticpolyisocyanates. Examples of aromatic polyisocyanates are tolylene 2,4-and 2,6-diisocyanate (TDI), diphenylmethane 4,4′-, 2,4′- and2,2′-diisocyanate (MDI), polyphenylene-polymethylene polyisocyanate(crude MDI), naphthylene 1,5-diisocyanate.

[0047] Examples of (cyclo)aliphatic diisocyanates or triisocyanates aretetramethylene 1,4-diisocyanate, hexamethylene 1,6-diisocyanate,isophorone diisocyanate, 2-methylpentamethylene diisocyanate, 2,2,4- or2,4,4-trimethylhexamethylene 1,6-diisocyanate,2-butyl-2-ethylpentamethylene diisocyanate, 1,4-diisocyanatocyclohexane,3-isocyanatomethyl-1-methyl-1-isocyanatocyclohexane,isocyanatopropylcyclohexyl isocyahate, xylylene diisocyanate,tetramethylxylylene diisocyanate, bis(4-isocyanatocyclohexyl)methane,lysine ester isocyanate, 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane,4-isocyanatomethyloctamethylene 1,8-diisocyanate and also their mixturesor the oligoisocyanates or polyisocyanates prepared therefrom.

[0048] The oligoisocyanates or polyisocyanates can be prepared from theabovementioned diisocyanates or triisocyanates or their mixtures bylinkage via urethane, allophanate, urea, biuret, uretdione, amide,isocyanurate, carbodiimide, uretonimine, oxadiazinetrione oriminooxadiazinedione structures.

[0049] The abovementioned isocyanates can also be modified, for exampleby incorporation of carbodiimide groups. The polyisocyanates are alsofrequently used in the form of prepolymers. These are reaction productsof the abovementioned polyisocyanates with polyol components. Use isusually made of isocyanate prepolymers, i.e. reaction products ofpolyols and polyisocyanates which have free isocyanate groups at the endof the chain. The prepolymers and pseudoprepolymers and theirpreparation are generally known and have been described many times. Inthe process of the present invention, particular preference is given tousing prepolymers having an NCO content in the range from 25 to 3.5% byweight.

[0050] In a preferred embodiment of the process of the presentinvention, MDI and/or crude MDI and biurets, isocyanurates andallophanates based on aliphatic isocyanates are used as isocyanatecomponents.

[0051] As compounds having at least two active hydrogen atoms,preference is given to using polyester alcohols and particularpreference is given to using polyetherols having a functionality of from2 to 8, in particular from 2 to 4, preferably from 2 to 3, and a meanmolecular weight in the range from 1000 to 8500 g/mol, preferably from1000 to 6000. Compounds having at least two active hydrogen atoms alsoinclude the chain extenders and crosslinkers which may also be used.Preferred chain extenders and crosslinkers are 2- and 3-functionalalcohols having molecular weights of less than 1000 g/mol, in particularin the range from 60 to 150. Examples are ethylene glycol, propyleneglycol, diethylene glycol, dipropylene glycol, polyethylene glycolhaving a molecular weight of less than 1000, polypropylene glycol havinga molecular weight of less than 1000 and/or 1,4-butanediol. Diamines canalso be used as crosslinkers. If chain extenders and crosslinkers areused, their amount is preferably up to 5% by weight, based on the weightof the isocyanates.

[0052] As catalysts for the production of the polyurethane foams of thepresent invention, it is possible to use the customary and knownpolyurethane formation catalysts, for example organic tin compounds suchas tin diacetate, tin dioctoate, dialkyltin dilaurate and/or stronglybasic amines such as triethylamine, pentamethyldiethylenetriamine,bis(dimethylaminoethyl) ether, 1,2-dimethylimidazole,dimethylcyclohexylamine, dimethylbenzylamine or preferablytriethylenediamine. The catalysts are preferably used in an amount offrom 0.01 to 5% by weight, preferably from 0.05 to 2% by weight, basedon the weight of the isocyanates.

[0053] As blowing agent for producing the polyurethane foams, preferenceis given to using water which reacts with the isocyanate groups toliberate carbon dioxide. It is also possible to use physically actingblowing agents, for example hydrocarbons such as n-pentane, isopentaneor cyclopentane or halogenated hydrocarbons such as tetrafluoroethane,pentafluoropropane, heptafluoropropane, pentafluorobutane,hexafluorobutane or dichloromonofluoroethane or acetals such as methylalin combination with or in place of water. The amount of the physicallyacting blowing agent is preferably in the range from 1 to 15% by weight,in particular from 1 to 10% by weight, and the. amount of water ispreferably in the range from 0.5 to 10% by weight, in particular from 1to 5% by weight, based on the weight of the compounds having at leasttwo active hydrogen atoms.

[0054] As auxiliaries and/or additives, it is possible to use, forexample, surface-active substances, foam stabilizers, cell regulators,external and internal mold release agents, fillers, pigments, hydrolysisinhibitors and also fungistatic and bacteriostatic substances.

[0055] In the production of the polyurethane foams of the presentinvention, the polyisocyanates and the compounds having at least twohydrogen atoms which are reactive toward isocyanate groups arepreferably reacted in such an amount that the equivalence ratio ofisocyanate groups to the sum of active hydrogen atoms is 0.7-1.8:1,preferably 0.7-1.2:1.

[0056] The polyurethane foams are preferably produced by the one-shotprocess, for example with the aid of the high-pressure or low-pressuretechnique. The foams can be produced in open or closed metallic molds orby continuous application of the reaction mixture to belts for producingslabstock foams.

[0057] It is particularly advantageous to employ the two-componentprocess in which, as indicated above, a polyol component and anisocyanate component are prepared and then foamed together. Thecomponents are preferably mixed at from 15 to 90° C., preferably from 20to 60° C. and particularly preferably from 20 to 35° C., and introducedinto the mold or applied to the belt. The temperature in the mold isusually in the range from 20 to 110° C., preferably from 30 to 60° C.and particularly preferably from 35 to 55° C.

[0058] In the case of the direct addition of the compounds (i) or (ii)in the production of the polyurethane foams, they can be added either tothe polyol component or the isocyanate component reference is given toadding (i) or (ii) to the polyol component.

[0059] The invention is illustrated by the following examples.

EXAMPLES Example 1 Production of a Polyurethane Foam

[0060] The polyurethane foam was produced using the foam formulationindicated in Table 1. Isocyanate component and polyol component werefoamed at an index of 100. TABLE 1 Formulation of the polyurethane foamproduced in Example 1 Constituent % by weight Lupranol 2040 5.0 Lupranol2047 87.0 Lupranol 3402 8.0 Lupragen N 201 0.15 Lupragen N 206 0.1Tegostab B 8418 3.2 Water 3.2 B 620/1 75.0 Lupranat M20W 25.0

[0061] After they had been produced, the foams were processed in a millto give foam particles.

Example 2 Immobilization of Polyethylenimine

[0062] The foam particles produced in Example 1 were shaken with 5%strength aqueous Lupasol solutions for 15 minutes, using 25 ml of theLupasol solutions per gram of foam. The foam particles were subsequentlyfiltered off, heated at 100° C. for 16 hours and then washed withdistilled water.

[0063] a) Lupasol® FG (BASF Aktiengesellschaft, polyethylenimine havingan MG of 800 g/mol)

[0064] b) Lupasol PR (BASF Aktiengesellschaft, polyethylenimine havingan MG of 2000 g/mol)

[0065] c) Lupasol® WF (BASF Aktiengesellschaft, polyethylenimine havingan MG of 25000 g/mol)

Example 3 Immobilization of Polyethylenimine

[0066] The foam particles produced in Example 1 were shaken with a 20%strength aqueous Lupasol® WF solution for 15 minutes, using 25 ml of thesolution per gram of foam. The foam particles were subsequently filteredoff, heated at 100° C. for 16 hours and then washed with distilledwater.

Example 4 Immobilization of Polyethylenimine

[0067] The foam particles produced in Example 1 were shaken with a 20%strength Lupasol® WF solution in acetone for 15 minutes, using 25 ml ofthe solution per gram of foam. The foam particles were subsequentlyfiltered off, heated at 100° C. for 16 hours and then washed withdistilled water.

Example 5 Immobilization of Polyethylenimine

[0068] The foam particles produced in Example 1 were shaken with a 20%strength aqueous Lupasol® P solution for 15 minutes, using 25 ml of thesolution per gram of foam. The foam particles were subsequently filteredoff, heated at 100° C. for 16 hours and then washed with distilledwater.

[0069] Lupasol® P (BASF Aktiengesellschaft, polyethylenimine having anMG of 750000 g/mol)

Example 6 Immobilization of Polyethylenimine

[0070] The foam particles produced in Example 1 were shaken with a 10%strength Lupasol® WF solution in acetone for 15 minutes, using 25 ml ofthe solution per gram of foam. The foam particles were subsequentlyfiltered off, heated at 100° C. for 16 hours and then washed withdistilled water.

Example 7 Immobilization of Polyethylenimine

[0071] The foam particles produced in Example 1 were shaken with a 27%strength Lupasol® WF solution in acetone for 15 minutes, using 25 ml ofthe solution per gram of foam. The foam particles were subsequentlyfiltered off, heated at 100° C. for 16 hours and then washed withdistilled water.

Example 8 Immobilization of Polyvinylamine

[0072] The foam particles produced in Example 1 were shaken with anaqueous polyvinylamine solution (k=88.9) for 15 minutes, using 25 ml ofthe polyvinylamine solution per gram of foam. The foam particles weresubsequently filtered off, heated at 100° C. for 16 hours and thenwashed with distilled water

[0073] a) Concentration of the polyvinylamine solution: 6.5%

[0074] b) Concentration of the polyvinylamine solution: 13%

Example 9 Immobilization of Polyvinylamine

[0075] The foam particles produced in Example 1 were shaken with anaqueous polyvinylamine solution (k=162) for 15 minutes, using 25 ml ofthe polyvinylamine solution per gram of foam. The foam particles weresubsequently filtered off, heated at 100° C. for 16 hours and thenwashed with distilled water

[0076] a) Concentration of the polyvinylamine solution: 2.1%

[0077] b) Concentration of the polyvinylamine solution: 4.2%

Example 10 Use of the Foams for Reducing the Concentration of HeavyMetals

[0078] The suitability of the foams produced in Example 2 for reducingthe concentration of heavy metals was qualified by way of example forthe case of the copper binding capacity. For this purpose, 2 g of eachfoam were shaken with 100 ml of copper solution for 2 hours. The copperconcentrations of the starting solution and of the solutions aftercontact with the foam particles were determined photometrically using acuvette tester from the company Dr. Lange. The following copper removalswere obtained.

[0079] Foam from Example 2a) 43.7 mg of Cu

[0080] Foam from Example 2b) 47.0 mg of Cu

[0081] Foam from Example 2c) 60.8 mg of Cu

Example 11 Use of the Foams for Decreasing the Concentration of HeavyMetals

[0082] The suitability of the foams produced in Examples 3 and 4 forreducing the concentration of heavy metals was qualified by way ofexample for the case of the copper binding capacity. For this purpose, 1g of each foam was shaken with 100 ml of copper solution for 2 hours.The copper concentrations of the starting solution and of the solutionsafter contact with the foam particles were determined photometricallyusing a cuvette tester from the company Dr. Lange. The results aresummarized in Table 2. TABLE 2 Comparison of the copper removalsachieved by the foams produced in Examples 3 and 4 Foam from Example 3Foam from Example 4 Available copper: bound copper: bound copper:  49mg/g of foam 45.5 mg/g of foam  43.8 mg/g of foam 101 mg/g of foam 73.7mg/g of foam  70.1 mg/g of foam 201 mg/g of foam 84.3 mg/g of foam 146.2mg/g of foam 299 mg/g of foam 94.6 mg/g of foam 178.4 mg/g of foam

Example 12 Use of the Foams for Reducing the Concentration of HeavyMetals

[0083] The suitability of the foams produced in Examples 3 and 5 forreducing the concentration of heavy metals was qualified by way ofexample for the case of the copper binding capacity. For this purpose, 1g of each foam was shaken with 100 ml of copper solution for 2 hours.The copper concentrations of the starting solution and of the solutionsafter contact with the foam particles were determined photometricallyusing a cuvette tester from the company Dr. Lange. The results aresummarized in Table 3. TABLE 3 Comparison of the copper removalsachieved by the foams produced in Examples 3 and 5 Foam from Example 3From from Example 5 Available copper: Bound copper: Bound copper:  49mg/g of foam 45.5 mg/g of foam  44.0 mg/g of foam 101 mg/g of foam 73.7mg/g of foam  82.0 mg/g of foam 201 mg/g of foam 84.3 mg/g of foam 129.4mg/g of foam 299 mg/g of foam 94.6 mg/g of foam 132.8 mg/g of foam 399mg/g of foam 94.6 mg/g of foam 136.4 mg/g of foam

Example 13 Use of the Foams for Reducing the Concentration of HeavyMetals

[0084] The suitability of the foams produced in Examples 4, 6 and 7 forreducing the concentration of heavy metals was qualified by way ofexample for the case of the copper binding capacity. For this purpose, 1g of each foam was shaken with 100 ml of copper solution for 2 hours.The copper concentrations of the starting solution and of the solutionsafter contact with the foam particles were determined photometricallyusing a cuvette tester from the company Dr. Lange. The results aresummarized in Table 4. TABLE 4 Comparison of the copper removalsachieved by the foams produced in Examples 3 and 5 Concentration of theFoam Foam Foam solution from Example 6 from Example 4 from Example 7Available copper: bound copper: bound copper: bound copper:  49 mg/g offoam  33.5 mg/g of foam  43.8 mg/g of foam  44.0 mg/g of foam 101 mg/gof foam  55.6 mg/g of foam  70.1 mg/g of foam  71.5 mg/g of foam 201mg/g of foam  76.4 mg/g of foam 146.2 mg/g of foam 142.3 mg/g of foam299 mg/g of foam 178.4 mg/g of foam 211.4 mg/g of foam 399 mg/g of foam239.0 mg/g of foam 499 mg/g of foam 258.0 mg/g of foam

Example 14 Use of the Foams for Reducing the Concentration of HeavyMetals

[0085] To determine the kinetics of heavy metal removal, which wasqualified by way of example for the case of copper removal, 0.1 g of thefoam produced in Example 4 was shaken with 100 ml of a 250 ppm coppersolution for various times. The copper concentrations of the startingsolution and of the solutions after contact with the foam particles weredetermined photometrically using a cuvette tester from the company Dr.Lange. The results are summarized in Table 5. TABLE 5 Kinetics of copperremoval by means of the foam produced in Example 4 Copper concentrationContact time of the solution Starting concentration 245 ppm t = 5 min.203 ppm t = 15 min. 195 ppm t = 30 min. 184 ppm t = 60 min. 172 ppm t =240 min. 138 ppm t = 1440 min. 137 ppm

Example 15 Use of the Foams for Reducing the Concentration of HeavyMetals

[0086] Foam particles produced in Example 7 were used for reducing theconcentration of various heavy metals. For this purpose, 1 g of the foamparticles were in each case shaken with 100 ml of a solution containing3000 ppm of heavy metal for 2 hours. The heavy metal concentrations ofthe starting solution and of the solutions after contact with the foamparticles were determined by means of atomic absorption spectrometry.The results are summarized in Table 6. TABLE 6 Removal of various heavymetals by means of the foam produced in Example 7 Starting remaining inthe heavy metal concentration solution removed mg/g of foam Nickel(II)3300 mg/l 2500 mg/l  80.0 mg/g of foam Iron(III) 2800 mg/l 2500 mg/l 30.0 mg/g of foam Lead(II) 2900 mg/l  185 mg/l 271.5 mg/g of foamCopper(II) 2990 mg/l  876 mg/l 211.4 mg/g of foam Zinc(II) 2800 mg/l1600 mg/l 120.0 mg/g of foam Mercury(II) 3000 mg/l  34 mg/l 296.6 mg/gof foam

Example 16 Regeneration of the Foams

[0087] 15 g of the foam particles produced as described in Example 5were shaken with 375 ml of a 2000 ppm copper chloride solution for 30minutes. The supernatant copper solution was subsequently filtered off,and the foam particles were regenerated using 0.5 N hydrochloric acid.The foam particles were loaded again by shaking them once more with 375ml of a 2000 ppm copper chloride solution (30 minutes). The results aresummarized in Table 7. TABLE 7 Removal of copper ions Copper ionsremoved Pass mg/g of foam 1 32.3 2 22.8 3 23.4 4 22.7 5 22.9 6 22.2 722.4 8 23.2 9 23.6 10 24.7 11 22.8 12 23.2 13 23.4 14 23.7 15 24.3 1623.7 17 22.5 18 22.8 19 23.4

Example 17 Use of the Foams for Purification of Wastewater from PaperManufacture

[0088] Foam particles produced as described in Examples 7 and 9b wereused for purifying an original wastewater from a paper factory. For thispurpose,. varying amounts of the foam were shaken with 50 ml of thewastewater for 30 minutes. The quality of the purification wasdetermined photometrically via the reduction in the absorbance at awavelength of 297 nm. The results are summarized in Table 8. TABLE 8Reduction in the absorbance of a wastewater from paper manufactureAbsorbance (l = 297 nm), Absorbance (l = 297 nm), % of foam from % offoam from Foam, g/50 ml Example 7 Example 9b Starting 100 100 solution0.05 g 85.4 95.3  0.1 g 55.5 92.0  0.2 g 26.3 79.9  0.3 g 23.9 63.3  0.5g 27.2 15.0

Example 18 Use of the Foams for Reducing the Concentration of Dyes

[0089] The wastewater of a dyeing works comprises mainly hydrolyzeddyes, and for this reason the reactive dye Remazol® Rot 198 (Dystar) wasdissolved beforehand in 0.01N sodium hydroxide solution and subsequentlyhydrolyzed on a waterbath at 60-70° C. for about 3 hours.

[0090] To decrease the concentration of the dye, 1 g of foam particlesfrom Example 7 were subsequently shaken with 50 ml of dye solution for 5hours, and the dye concentration in the solution was determinedphotometrically at the absorption maximum. Calibration was carried outusing hydrolyzed dyes with identical sample treatment. The results ofthe removal of Remazol Rot 198 at various pH values are summarized inTable 9. TABLE 9 Reduction in the concentration of the reactive dyeRemazol Rot 198 Dye removed Available dye mg/g mg/g of foam of foam pH =10 pH = 7 pH = 5 25 22 22 23 50 47 47 48 125 115 115 119 200 170 171 185

Example 19 Use of the Foams for Reducing the Concentration of Dyes

[0091] The wastewater of a dyeing works comprises mainly hydrolyzeddyes, and for this reason the reactive dye Procion Blue MX-R (Fluka,CAS: 13324-20-4) was dissolved beforehand in 0.01N sodium hydroxidesolution and subsequently hydrolyzed on a waterbath at 60-70° C. forabout 3 hours.

[0092] To decrease the concentration of the dye, 1 g of foam particlesfrom Example 7 was subsequently shaken with 50 ml of dye solution for 6hours, and the dye concentration in the solution was determinedphotometrically at the absorption maximum. Calibration was carried outusing hydrolyzed dyes with identical sample treatment. The results aresummarized in Table 10. TABLE 10 Reduction in the concentration of thereactive dye Procion Blue MX-R Available dye mg/g Dye removed of foammg/g of foam 25 25 50 50 120 99 200 198

Example 20 Use of the Foams for Reducing the Concentration of HeavyMetals

[0093] The suitability of the foams produced in Examples 8 and 9 forreducing the concentration of heavy metals was qualified by way ofexample for the case of the copper binding capacity. For this purpose, 1g of each foam was shaken with 100 ml of copper solution for 2 hours.The copper concentrations of the starting solution and of the solutionsafter contact with the foam particles were determined photometricallyusing a cuvette tester from the company Dr. Lange. The results aresummarized in Table 11. TABLE 11 Comparison of the copper removalsachieved by the foams produced in Examples 8 and 9 Available boundcopper copper Example 8a Example 8b Example 9a Example 9b  50 mg/g offoam 27.9 mg/g of foam 28.5 mg/g of foam  99 mg/g of foam 35.2 mg/g offoam  62.1 mg/g of 27.5 mg/g of  59.6 mg/g of foam foam foam 199 mg/g offoam 46.1 mg/g of foam 102.3 mg/g of 36.0 mg/g of  74.3 mg/g of foamfoam foam 299 mg/g of foam 48.7 mg/g of foam 113.4 mg/g of 47.0 mg/g of 85.4 mg/g of foam foam foam 401 mg/g of foam 138.0 mg/g of 52.0 mg/g of100.1 mg/g of foam foam foam 499 mg/g of foam 144.1 mg/g of 53.0 mg/g of101.0 mg/g of foam foam foam

[0094] Examples 21 to 31 relate to the use of the foams of the presentinvention for the adsorption of odorous substances.,

[0095] To assess the adsorption of odorous substances according to thepresent invention, various modified or unmodified polyurethane foamswere produced and tested. The odorous substances were simulated byacidic odorous substances such as acetic acid. The adsorption of themodel compounds was carried out at 25° C. in a controlled-temperaturecabinet having a capacity of 560 l. Concentrations of about 140-160 ppmv/v (v/v=volume-based concentrations) of model substance were set withinthe temperature-controlled cabinet. After the foam had been added, thedecrease in concentration was determined by means of gas chromatography.The Lupranols are various polyetherols which had been prepared usingvarious starters and differ in the amount of ethylene oxide/propyleneoxide; the Lupranats are various products based on MDI.

Example 21

[0096] An aromatic flexible polyurethane foam, hereinafter referred toas comparative system 1, was produced by intensive mixing of 105.2 g ofthe A component with 100 g of the B component (Index 100) with the aidof a stirrer at a rotational speed of 1250 rpm and transfer of thefoaming mixture to a plastic container having a capacity of 5 l, withthe components being made up as follows: Polyol component: 97.0 parts ofLupranol 2040 ® (BASF Aktiengesellschaft)  3.0 parts of Lupranol 2047 ®(BASF Aktiengesellschaft)  3.3 parts of water  0.6 part of Lupragen N107 ® (BASF Aktiengesellschaft)  0.8 part of aminopropylimidazol  0.5part of Tegostab B 8631 ® (Goldschmidt) B Component:   42 parts ofLupranat M 20 W ®   11 parts of Lupranat MES ®   47 parts of LupranatMI ®

Example 22

[0097] An aromatic flexible polyurethane foam, hereinafter referred toas comparative system 2, was produced by intensive mixing of 115.24 g ofthe A component with 100 g of the B component (Index 100) with the aidof a stirrer at a rotational speed of 1250 rpm and transfer of thefoaming mixture to a plastic container having a capacity of 5 l, withthe components being made up as follows: Polyol component:   95 parts ofLupranol 2045 ® (BASF Aktiengesellschaft)    5 parts of Lupranol 2047 ®(BASF Aktiengesellschaft) 10.71 parts of Lupranol 2030 ® (BASFAktiengesellschaft)  3.45 parts of water  0.48 part of Lupragen N 201 ®(BASF Aktiengesellschaft)  0.13 part of Lupragen N 206 ® (BASFAktiengesellschaft)  0.37 part of tetramethylhexamethylenediamine (BASFAktiengesellschaft)  0.1 part of Tegostab B 8680 ® (Goldschmidt) BComponent:   75 parts of Lupranat M 20 W ®   25 parts of Lupranat MP111 ®

Example 23

[0098] An aliphatic flexible polyurethane foam, hereinafter referred toas comparative system 3, was produced by intensive mixing of 110 g ofthe A component with 100 g of the B component (Index 110) with the aidof a stirrer at a rotational speed of 1250 rpm and transfer of thefoaming mixture to a plastic container having a capacity of 5 l, withthe components being made up as follows: Polyol component: 56 parts ofLupranol 2042 ® (BASF Aktiengesellschaft) 35 parts of Lupranol 2045 ®(BASF Aktiengesellschaft)  2 parts of water  3 parts of Lupragen N 209 ®(BASF Aktiengesellschaft)  2 parts of Lupragen N 201 ® (BASFAktiengesellschaft)  1 part of Lupragen N 206 ® (BASFAktiengesellschaft)  1 part of Kosmos 29 ® (Goldschmidt)  1 part ofTegostab B 8680 ® (BASF Aktiengesellschaft)

[0099] B Component:

[0100] 100 parts of Basonat HI 100® (BASF Aktiengesellschaft)

Example 24

[0101] To modify the polyurethane foams of Examples 1 to 3, the foamswere impregnated with an ethanolic KOH solution (KOH content=5% andsubsequently heated at 100° C.

Example 25

[0102] To modify the polyurethane foams of Examples 1 to 3, the foamswere impregnated with a 5% strength solution of polyethylenimine inacetone and subsequently heated at 100° C.

Example 26

[0103] A plate having dimensions of 20×30×1 cm³ was cut from the foamproduced in Example 2). This was subsequently introduced into atemperature-controlled cabinet having a capacity of 560 l in which anacetic acid concentration of about 140-160 ppm v/v (v/v=volume-basedconcentration) had previously been set. The decrease in the acetic acidconcentration was measured every five minutes by means of a gaschromatograph and is shown graphically in FIG. 1. The acetic acidconcentrations obtained using Basotect® (melamine-formaldehyde foam fromBASF Aktiengesellschaft) and an open-celled polystyrene foam are shownas a function of time for comparison.

Example 27

[0104] Plates having dimensions of 20×30×1 cm³ were in each case cutfrom the foams produced in Examples 1), 2) and 3). These weresubsequently introduced into a temperature-controlled cabinet having acapacity of 560 l in which an acetic acid concentration of about 140-160ppm v/v (v/v=volume-based concentration) had previously been set. Thedecrease in the acetic acid concentration was measured every fiveminutes using a gas chromatograph and is shown graphically in FIG. 2.

Example 28

[0105] Two plates having dimensions of 20×30×1 cm³ were cut from thearomatic polyurethane foam produced in Example 1). One of these plateswas additionally treated as described in Example 4). The results in FIG.3 show, for comparison, the decrease in the acetic acid concentration asmonitored by gas chromatography for the modified foam and the unmodifiedfoam. The acetic acid concentration was arbitrarily set as 100% at timet=0

Example 29

[0106] Two plates having dimensions of 20×30×1 cm³ were cut from thealiphatic polyurethane foam produced in Example 3). One of these plateswas additionally treated as described in Example 4). The results in FIG.4 show, for comparison, the decrease in the acetic acid concentration asmonitored by gas chromatography for the modified foam and the unmodifiedfoam.

Example 30

[0107] Two plates having dimensions of 20×30×1 cm³ were cut from thearomatic polyurethane foam produced in Example 1). One of these plateswas additionally treated as described in Example 5). The results in FIG.5 show, for comparison, the decrease in the acetic acid concentration asmonitored by gas chromatography for the modified foam and the unmodifiedfoam.

Example 31

[0108] Plates of various dimensions were cut from the aromaticpolyurethane foam produced in Example 1), and the plates were treated asdescribed in Example 5). The results in FIG. 6 show, for comparison, thedecrease in the acetic acid concentration monitored by gaschromatography for the modified foam pads of differing dimensions.

1. A composition, comprising: a polyurethane foam and a component whichis: (i) ethylenimine, polyethylenimine, polyvinylamine, polyvinylaminecopolymers, carboxymethylated polyethylenimines, phosphonomethylatedpolyethylenimines, quaternized polyethylenimines dithiocarbamatizedpolyethylenimines or a mixture thereof, (ii) alkali metal hydroxides,alkaline earth metal hydroxides, or a mixture thereof, or (iii) amixture of (i) and (ii).
 2. The polyurethane foam as claimed in claim 1,comprising component (i), wherein (i) is covalently bound to the polymerof the foam.
 3. The polyurethane foam as claimed in claim 1, in whichcomponent (ii) is sodium hydroxide, potassium hydroxide, or a mixturethereof.
 4. The polyurethane foam as claimed in claim 1, which containsfrom 0.1 to 80% by weight of (i), (ii), or a mixture thereof, based onthe weight of the foam. 5-9. (canceled)
 10. A shaped body, comprisingthe composition of claim 1.